Fix a bug where io redirection of builtins would not truncate files if the builtin did not produce any output

darcs-hash:20070324223430-ac50b-3f3d6fd35f5b82c59ecaa06b459fe2b61dc8f387.gz

exec.c

@@ -1317,6 +1317,8 @@ void exec( job_t *j )
 					( !sb_err->used ) &&
 					( !p->next );
 	
+				int has_file_redirect = 0;
+				
 				/*
 				  If the output of a builtin is to be sent to an internal
 				  buffer, there is no need to fork. This helps out the
@@ -1337,6 +1339,14 @@ void exec( job_t *j )
 					free( res );				
 				}
 
+				for( io = j->io; io; io=io->next )
+				{
+					if( io->io_mode == IO_FILE )
+					{
+						skip_fork = 0;
+					}
+				}
+				
 				if( skip_fork )
 				{
 					p->completed=1;